1st of all, nothing against a pakistani bowler earning extra money, but considering the prospect he brings, i thought i'l make a thread. 

Let's consider his physical structure. A 7 feet tall player. The problem with very tall person is that, the whole upper body weight puts a great stress on hip joint along with the spine. 

In normal circumstances, the joints modify itself to make the tension less. But for a sports person, the story becomes little different. 

With bowling, running, there'l be a drastic up and down of tension along the line of spine, hip joint, knee joint and most importantly, the ankle. Whilst a normal height, avg built person's body can take it, in case of irfan, this sudden burst of tension can lead to ligaments tear to say the least.

I believe he is a great asset to pakistan and should be carefully manage. Otherwise, a few injury can restrict his abilities and the sharpness may go little down.